Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/0061—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof characterized by the use of several polymeric components
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
  • C08J9/12—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a physical blowing agent
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/04—Homopolymers or copolymers of ethene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/26—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers modified by chemical after-treatment
  • C08L23/28—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers modified by chemical after-treatment by reaction with halogens or halogen-containing compounds
  • C08L23/286—Chlorinated polyethylene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2201/00—Foams characterised by the foaming process
  • C08J2201/02—Foams characterised by the foaming process characterised by mechanical pre- or post-treatments
  • C08J2201/03—Extrusion of the foamable blend
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2323/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
  • C08J2323/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2323/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
  • C08J2323/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment
  • C08J2323/04—Homopolymers or copolymers of ethene
  • C08J2323/06—Polyethene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2423/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2203/00—Applications
  • C08L2203/14—Applications used for foams
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/04—Homopolymers or copolymers of ethene
  • C08L23/06—Polyethylene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/04—Homopolymers or copolymers of ethene
  • C08L23/08—Copolymers of ethene
  • C08L23/0807—Copolymers of ethene with unsaturated hydrocarbons only containing four or more carbon atoms
  • C08L23/0815—Copolymers of ethene with unsaturated hydrocarbons only containing four or more carbon atoms with aliphatic 1-olefins containing one carbon-to-carbon double bond
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2314/00—Polymer mixtures characterised by way of preparation
  • C08L2314/06—Metallocene or single site catalysts

Definitions

• the present invention relates to polyolefin foams ultraflexibles.
• This type of foam can find its use as a joint sealing between two materials whose surfaces are irregular.
• a material can be a moisture barrier.
• This material must be able to be available as a continuous profile, in variable form, and must have good flexibility as well as excellent waterproofing. If we has such a material, the fact that it is foamed brings advantages in price and flexibility.
• the foamed material will be placed (by gluing or welding) on a rigid surface, with shapes may be irregular, and we will press on the surface on which the joint was applied a substrate, partially crushing the joint, in order to achieve watertight partitioning. They may, for example, be constituent panels of a roof or walls. If the installation must be able to be done manually, the force that one is able to exercise on the foam seal is limited. If the joint is too rigid, the force necessary to crush it evenly between the surface and the substrate affixed thereafter will be insurmountable.
• Known very flexible open cell foam seals which are suitable for the use described above are generally of a nature composite: for example open cell foam having a porosity accessible on the surface, therefore without external skin, very flexible, polyurethane, polyester or polyether, and which contain a strong liquid viscosity making it more difficult for moisture to pass through.
• the seal is delivered under prestressed in a plastic sheath, which is removed at the moment of the application.
• the cost of these composite seals is high, by nature polymers used for foam, by the use of a specific liquid for waterproofing and because of the conditioning of the joint.
• seals made of foamed materials having open cells and comprising an impermeable skin are described in patent EP 405103 respectively in US patent 4,931,484. They consist of homopolymer polyethylene, flexible polyethylene copolymers or their mixtures. Among homopolymers, low density polyethylene is preferred; among the flexible ethylenic copolymers, mention is made of EVA, EMA, EEA, EAA. EVA is the preferred flexible ethylenic copolymer.
• the bimodal structure of the cells (open or closed) is obtained by extruding the compositions at least at 5 ° C. above the temperature giving rise to a foam with predominantly closed cells.
• the foams thus obtained have mechanical properties expressed in the form of an upper compressibility limit, namely 68947 N / m 2 or less at 50% deformation, according to a draft standard ASTM “Specification for Backer Material for Use With Cold and Hot applied Joint Sealants Used with Portland Cement Concrete and Asphalt Pavement Joints ”.
• the examples cited in these references describe foams characterized by a compression of minimum 19994.6 N / m 2 at 50% deformation.
• the cell structure is described as either “medium” or "fine in size but with a few large cells present in the heart”.
• the object of the present invention is to produce foams which are much more flexible than those of the state of the art.
• ethylene homopolymer is meant the polymers manufactured at ethylene base including high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE).
• HDPE high density polyethylene
• LDPE low density polyethylene
• LLDPE linear low density polyethylene
• the preferred ethylene homopolymer is low polyethylene density (LDPE), preferably having a Melt Flow index of 0.2 to 20, preferably from 0.7 to 8.
• Flexible ethylene copolymers produced by a process high pressure are all those synthesized under high pressure, for example ethylene ethyl acrylate (EEA), ethylene acrylic acid (EAA), ethylene methacrylic acid (EMAA), ethylene vinyl acetate (EVA), ethylene butyl acrylate (EBA), ethylene methyl acrylate (EMA).
• EVA ethylene ethyl acrylate
• EAA ethylene acrylic acid
• EEMAA ethylene methacrylic acid
• EVA ethylene vinyl acetate
• EBA ethylene butyl acrylate
• EMA ethylene methyl acrylate
• the Melt Flow Index of these copolymers can vary from 0.2 to 25, preferably from 0.7 to 8. EVA, EBA, EMA are preferably used.
• foams according to the invention include less expensive materials than composite foams without external skin currently available.
• the foams according to the invention have naturally waterproof outer skin.
• compositions comprising a) an ethylene homopolymer AND / OR a flexible ethylene copolymer such as EVA, EMA, EBA, EEA, EAA and the like and b) a separate polymer from those designated in point a) in that it must have a melting point DSC lower by at least minimum 5 ° C (preferably 10 ° C) to that of the copolymer from point a), we gets a new kind of open cell foam with a unrivaled flexibility, aided by a particularly cellular structure fine and regular compared to the state of the art.
• a flexible ethylene copolymer such as EVA, EMA, EBA, EEA, EAA and the like
• Compression values are halved at least by compared to those obtained with foams representative of the preceding EP patents 405,103, respectively US 4,931,484.
• This morphology is very favorable for direct gassing, because the existence long branches leads to a phenomenon of elongational hardening high deformations, which greatly improves melt strength polymer (“Melt Strength”), and at the same time its foamability (possibility of reaching low densities).
• Melt Strength melt strength polymer
• the CPEs do not benefit of this structure with long side branches because they are synthesized at from HDPE, having a strongly linear structure and free from long type connection.
• HDPE is treated with chlorine in a suspension process, during which nucleators of growth and anti-caking agents: talc, calcium carbonate, stearate calcium.
• the CPE is delivered in the form of a powder which does not compact thanks to anti-caking agents. Chlorine levels can range from 10 to 60% depending on the applications.
• the foam advantageously comprises between 10 to 50% of chlorinated polyethylene and preferably between 20 to 40% of chlorinated polyethylene.
• the chlorinated polyethylene (CPE) will advantageously have between 10 and 50% of chlorine, preferably 20 to 40% of chlorine, or particularly preferably 30 to 36% of chlorine.
• the viscosity (DIN 54811-A / ISO / DIS 11443, 145s -1 , 190 ° C) of the CPE can vary from 500 Pa.s to 2500 Pa.s, preferably a viscosity of 700 Pa. S to 1500 Pa is chosen. s.
• the mixture can comprise in additionally between 5 and 95% metallocene polyethylene.
• the metallocene polyethylene will preferably have a lower density or equal to 915 kg / m3.
• the mixture contain 30 to 45% metallocene polyethylene having a density less than or equal to 915 kg / m3.
• the metallocene polyethylenes which can be used have a density of between 860 kg / m 3 and 915 kg / m 3 , which gives them elastomeric properties (particularly high elongation at break, greater than that of ethylene type copolymers radical).
• Possible co-monomers are butene C 4 , hexene C 6 , octene C 8 .
• the quantity and distribution of the co-monomer act on the density of the metallocene polyethylene and on the thermo-mechanical properties.
• the EXACT metallocene polyethylenes (EXXONMOBIL, co-monomer C 4 , C 6 or C 8 ), ENGAGE (Dupont Dow, co-monomer C 8 ) can be used.
• metallocene polyethylenes with a density less than or equal to 915 kg / m 3 have advantageous mechanical characteristics, in particular greater flexibility. As the examples show, the foams produced require a very low compressive stress.
• nucleating agents To further regulate the cell structure, one can use nucleating agents.
• passive nucleators such as talc, calcium carbonate, silica or stearate calcium
• active nucleating agents such as bicarbonate combinations soda and / or citric acid available on the market
• active agents are available in the form of masterbatches (masterbatch), based on the appropriate resin (polyethylene, copolymer ethylene, metallocene polyethylene, ).
• resin polyethylene, copolymer ethylene, metallocene polyethylene, .
• passive nucleating agents such as those mentioned above and “active” nucleating agents to optimize cell structure and the cost of the formulation, the "active" nucleating agents being generally more expensive than "passive” nucleating agents.
• the dosage of these nucleators will be adapted according to the desired cell structure. We will generally use from 0.1 to 10% by weight of active nucleating agents, including or not including passive nucleating agents previously defined.
• additives can be used to achieve properties particular for foam.
• We can cite, among others, anti-fire, agents antistatic, volume stabilizing agents, pigments, absorbers-reflectors infrared, anti-UV, antioxidants, ... which are known to humans art.
• the gases which can be used for foaming in direct gassing are known to those skilled in the art; they are generally volatile organic compounds, having a boiling point (at 1 atmosphere) lower than the melting point of the base resin.
• alkane hydrocarbons HFCs, CO 2 , atmospheric gases (CO 2 , N 2 , Ar, ).
• alkanes are the preferred physical blowing agents, especially C 3 and C 4 alkanes. More particularly, isobutane is used.
• the extruded foam is guided by a drawing machine practically without voltage, in a cooling section (air or water or both) to freeze the desired structure.
• the extruder can be a single screw extruder, co-rotating twin screw or counter-rotating.
• the extrusion temperature of the mixture in the die will be adjusted by those skilled in the art in order to obtain the required consistency of the foamed product. it means that a higher die temperature must be obtained than the temperature that would lead to the formation of closed cells.
• the mixture of polymers with different melting points favors obtaining mostly open cells within the foam, at a temperature higher.
• foams from the compositions of the present invention of multiple shapes: round, square profiles, shapes irregular concave or convex, .... Just extrude the mixture polymers + gas through a die with the design and shape required for give the desired expanded final shape.
• the compositions of the present invention give rise to foams so flexible that once the tube of foam formed, it collapses under its own weight.
• the tube stabilizes and becomes perfectly round again.
• a explanation is offered, namely that trapping air in the interior of the tube, combined with the diffusion of the foaming agent, maintains a hydrostatic overpressure which balances by restoring the natural form of the tube. Once the foam has cooled properly, you can release the pinch and the tube forms perfectly.
• the foam is extruded through a rectangular die, at 10 kg / h of polymer flow, with 1.05 kg of isobutane / h.
• the temperature of the polymer + gas mass at the outlet of the cylinder is 113 ° C. and the foam passes through an air-blowing ring, placed directly after the formation of the foam in the open air, to freeze the external surface. foam.
• the density is 27 kg / m 3 and the profile is a 14x9mm rectangle, counting ⁇ 250 cells / cm 2 . There are larger cells located in the center of the foam.
• the foam is open cell with an outer skin and has a certain flexibility.
• the foam is extruded through a small square die, at 10 kg / h of polymer flow, with 1.26 kg of isobutane / h.
• the temperature of the polymer + gas mass at the outlet of the cylinder is 113.9 ° C. and the foam passes through an air-blowing ring, placed directly after the formation of the foam in the open air, to freeze the outer surface of the foam.
• the density is 27 kg / m 3 and the profile is a rectangle of 8x8mm, counting ⁇ 450 cells / cm 2 .
• the foam is open cell with an outer skin and has improved flexibility, due to the thinner cell size on average. There are larger cells located in the center of the foam.
• the foam is extruded through the rectangular die of Comparative Example No. 1, at 10 kg / h of polymer flow rate, with 1.08 kg of isobutane / h.
• the temperature of the polymer + gas mass at the outlet of the cylinder is 101.1 ° C. and the foam passes through an air-blowing ring, placed directly after the formation of the foam in the open air, to freeze the external surface. foam.
• the density is 29 kg / m 3 and the profile is a 13x8.2mm rectangle with ⁇ 600 cells / cm 2 .
• the foam is open cell with an outer skin and has a much higher flexibility, not only because of the thinner cell size on average, but especially thanks to the incorporation of the CPE and the substitution of the LDPE polyethylene by the EBA copolymer.
• the cells are remarkably uniform over the entire section. Compression value (N / mm 2 ) according to ISO 3386/1 and / 2: Deformation imposed 1 2 3 10% 7643 2667 20% 12259 8342 4750 30% 16161 11700 6583 40% 19545 7792 50% 23866 19742 9458 60% 32304 13375

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• Chemical & Material Sciences (AREA)
• Polymers & Plastics (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Organic Chemistry (AREA)
• Materials Engineering (AREA)
• Engineering & Computer Science (AREA)
• General Chemical & Material Sciences (AREA)
• Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Paints Or Removers (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)

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Citations (4)

• 2003
  • 2003-02-20 EP EP03100409A patent/EP1449876A1/fr not_active Withdrawn
• 2004
  • 2004-02-16 PL PL376640A patent/PL209427B1/pl unknown
  • 2004-02-16 EP EP04711381A patent/EP1594919B1/fr not_active Expired - Lifetime
  • 2004-02-16 AT AT04711381T patent/ATE554137T1/de active
  • 2004-02-16 WO PCT/EP2004/050141 patent/WO2004074368A1/fr not_active Ceased
  • 2004-02-16 ES ES04711381T patent/ES2384516T3/es not_active Expired - Lifetime
  • 2004-02-16 DK DK04711381.6T patent/DK1594919T3/da active

Patent Citations (4)

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